Medium chain triglycerides alleviate non-alcoholic fatty liver disease through bile acid-mediated FXR signaling pathway: A comparative study with common vegetable edible oils.

With the global epidemic trend of obesity, non-alcoholic fatty liver disease (NAFLD) has become a significant cause of chronic liver disease, seriously affecting human health. Medium-chain triglycerides (MCT) with a fatty acid chain length varying between 6 and 10 carbon atoms (most sources from coconut and palm kernel oils), which exhibited activities to improve lipid metabolism, prevent cardiovascular diseases, and enhance immunity. However, the efficacy differences and potential mechanisms between MCT and traditional long-chain vegetable oils (palm oil, PA; high oleic peanut oil, OA) in obesity-induced NAFLD were still unclear. The present study treated obesity-induced NAFLD mice with different dietary lipids for 16 weeks. The results showed that MCT supplements significantly improved abnormal elevation of weight gain and blood lipids and reduced hepatic lipid accumulation to a greater extent than PA and OA. Furthermore, bile acid profiling results indicated that MCT significantly changed the composition of bile acids in the liver, reduced the concentrations of cholic acid (CA), deoxycholic acid (DCA), β-muricholic acid (β-MCA), and ursodeoxycholic acid (UDCA) and increased the concentrations of chenodeoxycholic Acid (CDCA), taurochenodeoxycholic acid （TCDCA), hyodeoxycholic acid (HDCA), and taurohyodeoxycholic acid (THDCA). Mechanistically, MCT supplement upregulated FXR signal and inhibited the expression of key genes for triglyceride synthesis in the liver, thereby reducing hepatic lipid accumulation. In summary, MCT exerted a superior effect on PA and OA in improving obesity-induced NAFLD. These results provided new evidence for the application of MCT in treating NAFLD.